Incandescent lamp.



M. M. MERRITT. INCANDESGENT LAMP.

APPLICATION FILED FEB. 24, 1906.

Patented Jan. 12, 1909.

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ATTY'S.

. UNITED STATES PATENT OFFICE.

MATTHEW M. MERRITT, OF MIDDLETON, MASSACHUSETTS, ASSIGNOR TO NATIONAL ELEC- TRIO LAMP COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

INCANDESCENT LAMP.

T 0 all whom it may concern:

Be it known that I, MATTHEW M. MER- RITT, a citizen of theUnited States, residing at Middleton, county of Essex, and State of Massachusetts, have invented an Improvement in Incandescent Lamps, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention relates to improvements in incandescent lamps, having more particularly for its object the provision of a lamp so constructed as to prevent, or render commercially impractica le, its renewal, or, in other words, the substitution, or attempted substitution, of a new filament for the oldone when the latter is burned out or otherwise rendered' useless or inefiicient.

It is a common practice to purchase at a relatively slight cost high grade lamps thus burned out, open the end or tip of the lamp and replace the old filament with a fresh one. The new filament having been attached to the leading-in wires, the lamp is exhausted by the usual process, the bulb sealed up, and the renewed or converted lamp in condition again for use. This renewing process is frequently conducted by irres onsible persons lacking the necessary skill and knowl edge in the art and employing inferiorv materials, so that its product, in any event an inferior one, is very often a low grade lamp, though having every appearance of a high grade one.

My invention aims to correct this practice, preventing possible injury to the reputation of the maker of the original lamp and deception of the ublic as Well.

In the escribed embodiment of m invention this is accomplished by origina ly so constructing the lamp as to prevent or offer hindrance to one or more steps of the usual renewing process.

My invention will be best understood by reference to the following description when taken in connection with the accompanying illustration of one or more specific embodiments thereof, while its scope will be more particularly pointedout in the appended claims. I

In the drawing s,-Figure 1 shows in elevation a lamp embodying one form of my Specification of Letters Patent.

Application filed February 24, 1906. Serial No. 302,671.

Patented Jan. 12, 1909.

invention; Fig. 2 shows an enlarged sectional detail, and Fig. 3 in plan the guarding device employed with the lamp illustrated in Fig. 1; Figs. 4 and 5 show a, modification thereof, and Figs. 6 and .7, a second modification.

In the ordinary renewal operation the tip of the old lamp bulb is first opened and the old filament subsequently removed throu h the opening formed, after which there is su stituted a fresh filament. A. short stem or tubulature is subsequently Welded on to the tip of the bulb at the opening therein and the lamp thereafter exhausted by the usual process.

While other means may be employed to hinder the consummation of the renewal process and means may be used for preventmg or obstructing other steps thereof without departing from the spirit of my invention, in the described embodiment thereof I provide means for obstructing, hindering or preventing the manipulation which is incidental to replacing the old filament by a fresh one.

In the drawings, particularly in Figs. 1-3, there is shown a common form of incandescent lamp provided with the usual glass bulb a, cemented or otherwise secured in the usual fashion to and within the lamp socket b and having the usual form of stem 0 through which pass the leading-in wires (1 terminating in the usual sealed-in platinum ends 0, the latter connected to the filament f. The filament is shown as fastened to the inwardly projecting ends of the platinum wires by the indmg action of a body of ordinary paste or graphite cement g, which is customarily emloyed for this purpose. After the lamp has con perforated at its tip the pasted joints are easily broken and the old filament ends pulled free by any suitable tool inserted in the bulb and the filament broken up and withdrawn through the smallopening in the bulb end. The platinum ends are then scraped or raked free of the old paste, this being ordinarily performed by a tool having a claw foot with a V-shaped opening, which is drawn lengthwise the wires and simultaneously turned to scrape them clean. The new filament having been inserted, also through the small perforation in the end of the bulb, and its ends held in juxtaposition to the platinum ends by one tool, a second pasteherein a dish width w carrying tool is inserted and paste wiped around the adjoining ends of the filament and leading-in wires, to secure the new filament in place. I

The described manipulation,-deal1ng as 1t does with delicate parts, and carried on, as it must be, at a disadvantage through the extremely small aperture at the end of the bulb, is an operation requiring skill and care and particu arly a considerable freedom and range of movements, for the active ends of the tools which engage the ends of the lat1- num wires; This is especially true in t e cementing or wiping operation. Furthermore, the installation of the filament in the renewal process, requires the platinum ends to be more or less bent or straightened in order to give the installed filamentthe requisite position in the lam bulb.

In the described em odiment of my invention I have provided means purposely to render difficult access to the ends of the leading-in wires, and particularly to prevent or obstruct both the wiping and the raking action incidental to the installation of a new filament. Any suitable means may be used for this purpose, but as shown in the drawings, I have rovided the guard h, com rising centrally perforated to e slid over the end of the anchor Wire sup ort 71 during the original construction of the amp, and secured thereto inany suitable fashion as by the glass bead 7'. This disk is secured to the anchor wire at about the same distance from the stem as the pasted joints and is provided with a pair of o positely disposed notches ls, through whic the ends of the leading-in wires pass when assuming their natural osition, said notches being of a liich referably but slightly clears the joints. is guard can be readily applied alter the installation of the original filament, which takes place before the stem is connected to or inclosed within the bulb, without particular trouble or expense, but when so applied willpractically prevent the installation of a second filament unless de-- struction or removal of the guard can be effected. The guard, however, must not only be removed from its sup ort to permit installation of the filament ut broken u and removed also from the lam throug the small end erforation of the ulb before the latter can he exhausted and sealed up.

By constructing the guard of some strong tough material, such as porcelain, indurated fiber, lava or other suitable substance, the attempted removal of the guard, its fracture and withdrawal will be attended with so much additional difficulty and expense as to form a commercial bar to the carrying out of the renewal process. If desired, however, some additional means might be employed for preventing the removal of'the guard or occasioning injury to the lamp if its removal were attempted. For example, in Fig. 2 I have shown the anchor wire 71, adjacent its attachment to the stem, materially weakened, as at l. The weakening of the anchor wire support can be readily effected-by a suitable tool at the time of the original construction of the lamp and can be so accomplished as to leave the wire with sufficient strength to suitably support the filament and guard, while of a strength less than that of its attachment to the guard, so that attempted removal of the guard will break the anchor wire itself. The guard being preferably constructed of insulating material, it is immaterial how small a clearance is left between the sides of the groove k and the pasted joints. If it is desired to protect or cover the ends of the leading-in w1res and the pasted joints for a greater portion of their length, the guard may be so constructed as to accomplish this in some such fashion as shown in Figs. 4 and 5 Where the grooves are surrounded by the ribbed or raised portion m. v In Figs. 6 and 7 I have shown a modified form of the guard illustrated in Figs. 2 and 3, the modified form having an inwardly curved projecting edge or, which curves toward the stem, and more eflectually prevents the use of any tool for working over the ends of the platinum wires while the guard is in position. If desired, the under surface of the guard or that nearest the bulb tip could be utilized by suitably preparing the same as a reflecting surface to assist in'reflecting the light of the filament.

It will be obvious that as a means for preventing renewal, my invention is efiectual if so applied or constructed as to hinder access to one joint only or the end of one leadin -in wire only. It is also to be understood t at my invention is not limited to the location shown for the guarding means described, but that the same might be positioned further away from the stem end, or any suitable location where it will offer the desired hindrance to installing the new filament.

While I have shown and described one form of my invention, it is to be understood that the same is not limited to the details shown or described or the particular way in which the invention is carried into effect, but that extensive departures from its described form may be made without deviating from the spirit thereof.

laims.

1. A non-renewable incandescent lamp having a bulb, filament and leading-in wires and means independent of the filament fastening purposely to hinder access to the end of a leading-in wire.

2. A non-renewable incandescent lamp provided with leading-in wires and a guard or the end of a leading-in wire said guard being independent of the filament fastening.

3. A non-renewable incandescent lamp having leading-in wires and a filament attached thereto by pasted joints and an independent guard for a pasted joint.

4. A non-renewable incandescent lamp having means for preventing the renewal thereof, said means acting to obstruct the installation of the new filament. I

5. A non-renewable incandescent, lamp having leading-in wires, a filament attached thereto, and means to obstruct the attachment of a new filament to the leading-in wires.

6. A non-renewable incandescent lamp having leading-in wires, a filament attached thereto by pasted joints, and means to prevent the raking off from the wire ends of the old paste on theatteinpted renewal of the lamp.

7. A non-renewable incandescent lamp having leading-in wires, a filament attached thereto b pasted joints, and means for preventing tl ie installation of a fresh filament, said means operating to obstruct the pasting of the new filament to the ends of the leading-in wires.

8. A non-renewable incandescent lamp having leading-in wires and guarding means covering a leading-in wire end said guarding means being independent of the filament fastening.

9. A non-renewable incandescent lamp having leading-in wires, a filament, pasted joints between the leading-in wires an ament, and independent guarding means covering a pasted joint.

10. A non-renewable incandescent lamp having leading-in wires, a filament secured thereto, an anchor wire support for the filament, and means supported by the anchor wire for obstructing access to a leading-in wire end.

11. A non-renewable incandescent lamp having a stem, leading-in wires, a filament attached thereto, and means supported by the stem for obstructing access to the end of a leading-in wire.

12. A non-renewable incandescent lamp having leading-in wires, a filament, an anchor wire and a member su ported by the anchor wire and embracing a eading-in wire end.

13. A non-renewable incandescent lamp having leading-in wires, a filament, and means supported by the stem and embracing a leading-in wire end.

14. A non-renewable incandescent lamp having means to prevent the substitution of a new filament for the old one said means being removable only b injury to the lamp.

15. A non-renewa le incandescent lamp having a filament and anchor wire support thereon, means to cause injury to the anchor wire on attempted renewa of the lamp.

16. A non-renewable incandescent lamp having a bulb a, stem 0, the filament f, jointsg between the wire ends e and the filament and guard h associated with the same an independent of the filament fastening.

17. A non-renewable incandescent lamp having a filament, an anchor wire support, and reflecting means secured to the anchor wire support.

18. A non-renewable incandescent lamp having leading-in wires, a filament secured thereto, and means within the lamp space for obstructing access to the leading-in wire ends and independent of the ing.

19. A non-renewable incandescent lamp having a stem, a bulb, leading-in wires passing through the'stem of the bulb, a filament joined to said leading-in wires, and a guard associated with the filament and leading-in wires for obstructing access to the latter from the opposite end of the lamp and independent of the filament fastening.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

MATTHEW M. MERRITT. Witnesses: I I

. NINA B. SHIRLEY,

THOMAS B. BooTH.

filament fastenleading-in wires e, 

